This invention relates generally to the field of surface treatments and coatings for substrates and surfaces, and more particularly relates to treatments and coatings that possess anti-graffiti properties.
A common problem encountered with exterior surfaces that are exposed in public places, such as building walls, storage tanks, railroad cars, etc., is that such surfaces are often defaced and vandalized with spray paint or other marking materials by so-called graffiti artists. This is a worldwide problem and the total aggregate of the time and expense involved in the removal or covering over of the graffiti is immense.
One solution to address the graffiti problem is to provide coatings for the surfaces that prevent the spray paint or other marking material from properly adhering to the surfaces at the time it is applied, such that it becomes impossible for the graffiti artist to create a work of acceptable quality, thereby discouraging the effort. Another solution is to provide coatings that, while not affecting the adherence of the spray paint to any great degree at the time of application, reduce the adhesion of the cured paint such that it is easily removed from the surface at a later time, such as by pressure washing or wiping with solvents, for example. Many common anti-graffiti coatings are polyurethane-based. Unfortunately, these PU coatings and similar coatings are only surface coatings and are therefore considered as sacrificial coatings, in the sense that the anti-graffiti coatings need to be reapplied after only a few cleanings with solvents or by pressure washing because the cleaning process removes the outer layer of the anti-graffiti coating along with the spray paint. In addition, the vandal community has learned to remove the known anti-graffiti coatings using fire or acids prior to vandalizing the surfaces.
It is an object of this invention to provide a novel coating that possesses anti-graffiti properties, such that graffiti applied to the coating is easily removed. It is a further object to provide such a coating that is a penetrating coating, such that it is not merely a surface coating. It is a further object to provide such a penetrating coating that is applicable to most surfaces, including metal, organic or inorganic surfaces. It is a further object to provide such a penetrating coating that is highly resistant to fire or chemical attack, and which provides a surface with high surface tension to reduce the adhesion of the paint. It is a further object to provide such a penetrating coating that has a long working life and remains effective over many cleanings by solvents or pressure washing, for example up to 25 to 30 cleanings. This object and additional objects not expressly stated will become apparent upon review of the remaining disclosure.